Positive stop systems and methods for extrusion press

ABSTRACT

Systems, devices, and methods are described for extruding a material. In certain embodiments, an extrusion press system includes an extrusion die supported by a first support structure and a centering insert supported by a second support structure, wherein the centering insert guides a material to be extruded into the extrusion die. A positive stop may be coupled to the first support structure and extend towards the second support structure, wherein the positive stop defines a travel distance between the first support structure and the second support structure. In certain embodiments, movement of the second support structure towards the first support structure is limited by the positive stop to the travel distance. In certain embodiments, the positive stop is configured to adjust the travel distance.

BACKGROUND

Deformation is the process of forcing a piece of material to permanentlychange its thickness or shape, and some deformation techniques includeforging, rolling, extruding, and drawing. Deformation of a materialtypically generates heat. In the context of extrusion processes, excessheat at the interface between two components can contribute to wear andresult in the production of flash, where flash is the undesirablepassage of the extrusion material through clearance spaces between thetwo components. Present systems thus have limited operational run timesbecause of the generation of excess heat and associated problems.

SUMMARY

Disclosed herein are systems, devices, and methods for extruding amaterial. In certain embodiments, the systems, devices, and methodsinclude a positive stop between the extrusion die and a componentpositioned against the extrusion die. In certain embodiments, theextrusion die is a rotating extrusion die. The positive stops may reduceand/or eliminate the occurrence of flash at an interface between theextrusion die and the component. For example, the positive stops mayreduce the amount of heat at the interface. In some embodiments thecomponent is a centering insert that guides a material to be extrudedinto the rotating extrusion die.

In one aspect, the systems, devices, and methods include an extrusionpress system comprising an extrusion die supported by a first supportstructure, a centering insert supported by a second support structure,wherein the centering insert guides a material to be extruded into theextrusion die, and a positive stop coupled to the first supportstructure and extending towards the second support structure, whereinthe positive stop defines a travel distance between the first supportstructure and the second support structure. In certain implementations,the extrusion die rotates within the first support structure, and thecentering insert is positioned against the extrusion die and does notrotate. The centering insert may include gripping features thatfrictionally engage the material to be extruded and thereby prevent thematerial from rotating while engaged and as the material enters therotating extrusion die. In certain implementations, the extrusion presssystem further comprises a second positive stop.

In certain implementations, the first support structure is stationary,the second support structure is configured to move relative to the firstsupport structure, and movement of the second support structure towardsthe first support structure is limited by the positive stop to thetravel distance. In certain implementations, the centering insert is aconsumable part that is partially consumed when the second supportstructure moves towards the first support structure a distance of thetravel distance. In certain implementations, the travel distance isbetween about zero inches and about 100/1000 inch. In certainimplementations, the travel distance is between about 10/1000 inch andabout 50/1000 inch. In certain implementations, the travel distance isbetween about 10/1000 inch and about 30/1000 inch. In certainimplementations, the travel distance is about 20/1000 inch.

In certain implementations, the positive stop is configured to adjustthe travel distance. For example, the positive stop may include anadjustable portion that rotates about a threaded shaft for increasing ordecreasing the travel distance. In certain implementations, the positivestop comprises an adjustable portion that slides along a shaft forincreasing or decreasing the travel distance. In certainimplementations, the positive stop comprises a recess configured to matewith a plurality of end portions, each respective end portion having arespective thickness for increasing or decreasing the travel distance.In certain implementations, the positive stop further comprises athrough-hole into which a locking pin is positioned.

In one aspect, a method for extruding a material is provided thatincludes positioning a centering insert in a first position against anextrusion die, exerting a force on the centering insert to maintain adesired pressure of the centering insert against the extrusion die,wherein the force moves the centering insert from the first position toa second position, and preventing further movement of the centeringinsert at the second position. In certain implementations, uponpreventing further movement, a pressure of the centering insert againstthe extrusion die decreases relative to the desired pressure. In certainimplementations, the force continues to be exerted while movement of thecentering insert is prevented at the second position. In certainimplementations, a distance between the first position and the secondposition defines a travel distance. In certain implementations, themethod further includes adjusting the travel distance. In certainimplementations, the extrusion die rotates, and the centering insertdoes not rotate.

In one aspect, an extrusion press system is provided that comprisesextrusion means supported by a first support structure, guiding meansfor guiding a material to be extruded into the extrusion means, theguiding means supported by a second support structure, and means forlimiting movement of the second support structure with respect to thefirst support structure. In certain implementations, the extrusion meansrotates within the first support structure, and the guiding means ispositioned against the extrusion means and does not rotate. The guidingmeans may include gripping features that frictionally engage thematerial to be extruded and thereby prevent the material from rotatingwhile engaged and as the material enters the rotating extrusion means.In certain implementations, the extrusion press system further comprisesa second means for limiting movement of the second support structurewith respect to the first support structure.

In certain implementations, the first support structure is stationary,the second support structure is configured to move relative to the firstsupport structure, and movement of the second support structure towardsthe first support structure is limited by the limiting means to a traveldistance. In certain implementations, the guiding means comprises aconsumable part that is partially consumed when the second supportstructure moves towards the first support structure a distance of thetravel distance. In certain implementations, the travel distance isbetween about zero inches and about 100/1000 inch. In certainimplementations, the travel distance is between about 10/1000 inch andabout 50/1000 inch. In certain implementations, the travel distance isbetween about 10/1000 inch and about 30/1000 inch. In certainimplementations, the travel distance is about 20/1000 inch.

In certain implementations, the limiting means is configured to adjust atravel distance. For example, the limiting means may include anadjustable portion that rotates about a threaded shaft for increasing ordecreasing the travel distance. In certain implementations, the limitingmeans comprises an adjustable portion that slides along a shaft forincreasing or decreasing the travel distance. In certainimplementations, the limiting means comprises a recess configured tomate with a plurality of end portions, each respective end portionhaving a respective thickness for increasing or decreasing the traveldistance. In certain implementations, the limiting means furthercomprises a through-hole into which a locking pin is positioned.

Variations and modifications of these embodiments will occur to those ofskill in the art after reviewing this disclosure. The foregoing featuresand aspects may be implemented, in any combination and subcombination(including multiple dependent combinations and subcombinations), withone or more other features described herein. The various featuresdescribed or illustrated herein, including any components thereof, maybe combined or integrated in other systems. Moreover, certain featuresmay be omitted or not implemented.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other objects and advantages will be apparent uponconsideration of the following detailed description, taken inconjunction with the accompanying drawings, in which like referencecharacters refer to like parts throughout, and in which:

FIG. 1 shows a schematic side elevation view of illustrative positivestops in an extrusion press system according to certain embodiments;

FIGS. 2-4 show various side elevation views of illustrative adjustablepositive stops for the extrusion press system of FIG. 1 according tocertain embodiments; and

FIG. 5 shows a side elevation view of an illustrative extrusion presssystem that includes positive stops according to certain embodiments.

DETAILED DESCRIPTION

To provide an overall understanding of the systems, devices, and methodsdescribed herein, certain illustrative embodiments will be described.Although the embodiments and features described herein are specificallydescribed for use in connection with extrusion press systems, it will beunderstood that all the components, connection mechanisms, manufacturingmethods, and other features outlined below may be combined with oneanother in any suitable manner and may be adapted and applied to systemsto be used in other manufacturing processes, including, but not limitedto cast-and-roll, up-casting, other extrusion, and other manufacturingprocedures. Furthermore, although certain embodiments described hereinrelate to extruding metal tubing from hollow billets, it will beunderstood that the systems, devices, and methods herein may be adaptedand applied to systems for extruding any suitable type of product.

The extrusion press system operates using frictional heat generated froma non-rotating hollow billet contacting a rotating die to facilitatedeformation and extrusion of the billet. There is thus no requirement ofpre-heating the billets or the rotating die before the extrusion. Theamount of heat generated is generally determined by the rate at whichthe billets are fed into the rotating die (e.g., controlled by thepress-ram speed of the press-ram elements 130, 140 of FIG. 5) and therotation speed of the die (e.g., controlled by the rotation speed of thespindle 172 of FIG. 5), as well as the interior profile of the rotatingdie. Higher press-ram speeds and spindle rotation speeds generaterelatively greater amounts of heat.

The rotating die forms the outer diameter of an extruded tube producedby the extrusion press system, and a mandrel bar tip positioned withinthe rotating die forms the inner diameter of the extruded tube. Incertain embodiments, chilled process water, or any other suitablecooling fluid, is used to cool the process elements including therotating die, the centering insert, the billets, and the gear box oil,as well as the extruded tubing product. Unlike conventional extrusiontechniques, the extrusion press system of the present disclosure doesnot require any container within which to hold the billet for extrusion.Therefore the billets to be extruded preferably have sufficient columnstrength to withstand the pressure applied by the press-ram elementsduring the extrusion process. A programmable logic controller, or PLC,controls all or a subset of movements of the extrusion press systemwhile the system is set in automatic mode.

FIG. 1 shows a schematic side elevation view of positive stops 30, 40 inan extrusion press system 5 according to certain embodiments. Theextrusion press system 5 includes an extrusion die 10 supported by adie-backer plate or support structure 12. In some embodiments, theextrusion die 10 rotates within the support structure 12. For example,the extrusion die 10 may be coupled to a spindle (e.g., spindle 172 ofFIG. 5) operated by a motor. A centering insert 20 is positioned againstthe extrusion die 10 and supported by a platen or support structure 22.The centering insert 20 guides a material to be extruded into theextrusion die 10. For example, the centering insert 20 is hollow alongits length so that the material to be extruded passes through thecentering insert 20 before entering the extrusion die 10. The centeringinsert 20 preferably does not rotate. In some embodiments, the centeringinsert 20 has one or more gripping features (e.g., teeth, grooves, orother detents) that frictionally engage the material to be extruded andthereby prevent the material from rotating while engaged.

As shown in FIG. 1, a positive stop 30 is coupled to the first supportstructure 12 and extends towards the second support structure 22, with agap 34 of distance d₁ between a contact surface 30 a of the positivestop 30 and a contact surface 22 a of the second support structure 22.During operation, the first support structure 12 is stationary and thesecond support structure 22 moves relative to the first supportstructure 12. For example, one or more piston/cylinder drive units maybe coupled to the support structure 22 to advance and optionally retractthe structure. In certain embodiments, the second support structure 22moves in a direction towards the first support structure 12 (along arrowA) and a direction away from the first support structure (opposite arrowA). The positive stop 30 therefore defines a travel distance d₁ betweenthe respective support structures 12, 22. Although the positive stop 30is shown as coupled to and extending from the first support structure 12towards the second support structure 22, other configurations may beused. For example, in some embodiments, a positive stop may be coupledto the second support structure 22 and extend towards the first supportstructure 12, with a gap between respective contact surfaces of thepositive stop and first support structure 12. Any suitable arrangementfor preventing motion of one (or more) of the support structures may beused.

The movement of the second support structure 22 towards the firstsupport structure 12 is limited by the positive stop 30 to the traveldistance d₁. That is, the positive stop 30 acts as a physical stop orbarrier to the movement of the support structure 22. During operation,for example, the centering insert 20 is positioned against the extrusiondie 10 as shown in FIG. 1. From that position, the second supportstructure 22 can move (together with the centering insert 20) towardsthe first support structure 12 by a distance up to the travel distanced₁. For example, in some embodiments, the centering insert 20 is aconsumable part that is partially consumed when the second supportstructure 22 moves towards the first support structure 12 by a distanceup to the travel distance. In some embodiments, whether or not anycomponents are consumable, compression of the respective components(e.g., the adjacent die 10/insert 20) allows for movement of the supportstructure 22 by a distance up to the travel distance.

As discussed above, the extrusion die 10 may be a rotating extrusiondie, and the centering insert does not rotate, but serves to guide amaterial to be extruded into the rotating extrusion die. The centeringinsert 20 is positioned against the extrusion die 10 to minimize anyclearance between the two components. A force is exerted on thecentering insert 20 (e.g., by way of the support structure 22) tomaintain a desired pressure of the centering insert 20 against theextrusion die 10 during operation. This applied pressure maintains aseal between the two components. It is desirable to spread the work doneby the extrusion die across the length of the die to avoid thegeneration of excess heat at the entrance of the extrusion die. In someembodiments, however, the amount of pressure applied can causeundesirable heat generation at the interface of the centering insert 20and the extrusion die 10 (e.g., because the extrusion die 10 rotates andthe centering insert 20 does not rotate). Such heat can prematurely heatthe material being extruded as it enters the die, causing a “flash” ofthe material, where flash is the undesirable passage of the extrusionmaterial through clearance spaces between the extrusion die and thecentering insert.

The positive stop 30 reduces flash and/or other undesirable heatgenerated at the entrance of the die by preventing movement of thecentering insert relative to the rotating extrusion die after a givenamount of travel. For example, the force exerted on the centering insert20 can move the centering insert 20 along the direction of arrow A froma first position (e.g., shown in FIG. 1) to a second position (e.g.,displacement of travel distance d₁). At the second position, thepositive stop 30 prevents further movement of the centering insert 20(notwithstanding, in some embodiments, the continuous application offorce at that position). Any suitable travel distance may be used in theextrusion press systems of the present disclosure, including, forexample, a travel distance of zero when the positive stop is positionedagainst the centering insert. In some embodiments, the travel distanceis between zero inches and 100/1000 inch. In some embodiments, thetravel distance is between 10/1000 inch and 50/1000 inch. In someembodiments, the travel distance is between 10/1000 inch and 30/1000inch. For example, a travel distance of 20/1000 inch has been used inextrusion press systems for the continuous and uninterrupted extrusionof materials.

When the centering insert 20 reaches the second position and furthermovement is prevented, the pressure of the centering insert 20 againstthe extrusion die 10 decreases relative to the pressure exerted whilethe centering insert 20 was moving. This decreased pressure is enough toallow for continuous extrusion of a material (e.g., there is asufficient seal between the centering insert and the extrusion die), yetreduced enough to prevent the generation of excess heat that can lead tounwanted flash. Moreover, this decreased pressure can increase the lifeof various components of the extrusion press system 5. For example, thecentering insert 20 is typically a consumable part, and duringoperation, portions of the extrusion die 10 may also be consumed. Absenta positive stop, the force exerted on the centering insert 20 tomaintain pressure on the extrusion die 10 may cause a substantialportion of the centering insert 20 and/or extrusion die 10 to beconsumed as a result of frictional contact, in some cases leading to ahalt in the extrusion process to replace the part(s). Limiting thetravel distance of the centering insert, however, allows for minimal, ifany, consumption of the part(s). In certain embodiments, someconsumption of the centering insert and/or extrusion die 10 is desirablebecause controlled heat deformation of the centering insert and/orextrusion die 10 at the interface with the die may contribute to theseal between the rotating extrusion die and the non-rotating centeringinsert.

In some embodiments, a single positive stop may be used to limit themovement of a support structure. In some embodiments, more than onepositive stop may be used to limit the movement of a support structure.For example, as shown in FIG. 1, a second positive stop 40 in theextrusion press system 5 is coupled to the first support structure 12and extends towards the second support structure 22, with a gap 36 ofdistance d₂ between a contact surface 40 a of the positive stop 40 and acontact surface 22 b of the second support structure 22. The contactsurfaces 22 a/22 b of the second support structure 22 are shown as beingpart of the same planar surface 22 c of the support structure, althoughany surfaces could be used, so long as the gap distances d₁ and d₂(e.g., the amount of travel) are preferably the same. This prevents thepositive stops 30, 40 from causing different portions of the structureto move different amounts. For example, in some embodiments, the twopositive stops 30, 40 may have different respective lengths, yet theallowed travel distances d₁ and d₂ are the same. Although two positivestops 30, 40 are depicted, it will be understood that any suitablenumber of positive stops may be provided to limit the travel distance ofa support structure. Furthermore, the positive stops may be provided inany suitable arrangement. For example, in a system having three positivestops, each of the positive stops may be spaced about the extrusion die10 in a generally triangular pattern.

In some embodiments, the travel distance (e.g., travel distance d₁ andd₂) may be adjusted prior to or during operation of the extrusion presssystem 5. For example, prior to operation, the positive stops 30, 40 maybe removed and replaced with positive stops allowing a differentrespective travel distance. In some embodiments, prior to or duringoperation, the positive stops are configured to adjust the traveldistance. As shown in FIG. 2, a positive stop 300 includes a firstportion 302 and a second portion 304. The second portion 304 is anadjustable portion that, when adjusted, changes the respective traveldistance allowed by the positive stop 300. For example, the adjustableportion 304 can rotate about a threaded shaft 306 to increase ordecrease the travel distance allowed by the contact surface 304 a of thepositive stop 300. There are many variations of positive stops having anadjustable portion. For example, as shown in FIG. 3, a positive stop 310includes a first portion 312 and a second portion 314. The secondportion 314 is an adjustable portion that, when adjusted, changes therespective travel distance allowed by the positive stop 310. Theadjustable portion 314 can slide along a shaft 316 to any position alongthe shaft. In some embodiments, the shaft 316 has a plurality of holes317 that align with a respective through-hole 319 in the adjustableportion 314. When aligned, a locking pin 318 may be placed within thethrough-hole 319 to secure the adjustable portion 314 in place with thehole 317. In some embodiments, a similar locking mechanism may be usedwith the positive stop 300 discussed above for preventing rotation ofthe adjustable portion 304, when locked, about the threaded shaft 306.

In some embodiments, a positive stop is configured to adjust a giventravel distance without an adjustable portion. For example, as shown inFIG. 4, a positive stop 320 comprises a first portion 322 thatoptionally receives removable end portions. The first portion 322 has arecess 324 formed in a distal end 322 a thereof that is configured tomate with a plurality of end portions 326, 328, each respective endportion having a respective thickness for increasing or decreasing thetravel distance allowed by the positive stop 320. End portion 326 has acontact surface 326 a and a connector 327 that is received within therecess 324. End portion 328 similarly has a contact surface 328 a and aconnector 329 that is received within the recess 324. The end portions326, 328 have different respective thicknesses t₁, t₂ that changes therespective travel distance allowed by the positive stop 320. When no endportion is used, the positive stop 320 has yet another travel distanceallowed by the contact surface 322 a of the first portion 322. In someembodiments, a similar locking mechanism to that discussed above inconnection with FIG. 3 may be used with the positive stop 320 forpreventing removal, when locked, of the end pieces.

As discussed above, the positive stops may be configured to adjust thetravel distance during operation of the extrusion press system. In someembodiments, the adjustable portion of the positive stop (e.g.,adjustable portions 304, 314) can be adjusted manually or using the PLCsystem to change the travel distance without interruption of theextrusion process. Manual adjustment may be done by hand or by usingtools to prevent the risk of injury. Adjustment using the PLC system isautomatic or in response to an operator request, and may cause theadjustment of adjustable portions that are electro-mechanicallycontrolled (e.g., a piston-cylinder arrangement). Thus adjustment of thetravel distance may be done at any time during operation of theextrusion press system. In some embodiments, the travel distance can beincreased stepwise during operation. A first travel distance is set anda support structure moves by the first travel distance until it contactsthe positive stop. After a suitable amount of time, the travel distancemay be increased to a second travel distance, and the support structureagain moves until contacting the positive stop. Further stepwise (orcontinuous) adjustments to the travel distance can be made at any time.This allows an operator to control, throughout the extrusion process,the heat generated at the interface between components of the extrusionpress system (e.g., the extrusion die 10 and the centering insert 20).

The positive stops of the present disclosure (e.g., positive stops 30,40, 300, 310, 320) may be used for forming an extruded material in anysuitable system including, for example, the extrusion press systemsdescribed in U.S. patent application Ser. No. 13/650,977, filed Oct. 12,2012, the disclosure of which is hereby incorporated by reference hereinin its entirety. For example, positive stops 154, 156 may beincorporated into the extrusion press system of FIG. 5, which shows anextrusion press system 200 according to certain embodiments. Theextrusion press system 200 includes a mandrel carriage section 280 and aplaten structure section 290. The mandrel carriage section 280 includesa mandrel bar 100, fluid clamps or cooling elements 102 and 104, mandrelgrips or gripping elements 106 and 108, and a billet delivery system.The mandrel carriage section 280 is supported by a physical carriagestructure, which is not shown in FIG. 5 to avoid overcomplicating thedrawing, but which carriage structure serves as a mount for thecomponents of the mandrel carriage 280. The platen structure section 290includes an entry platen 120 and a rear die platen 122, press-ramplatens 130 and 140, a centering platen 152, and a rotating die 160 thatpresses against the rear die platen 122. The platen structure section290 is supported by a frame 190 that may also serve as a mount for themotor 170 and related gearbox components (not shown). The directionalong which billet loading, transport, and extrusion occurs according tothe extrusion press system 10 is denoted by arrow B. The extrusion presssystem 200 may be operated, at least in part, by a PLC system thatcontrols aspects of the billet delivery subsystem 220, extrusionsubsystem 240, and quenching or cooling subsystem 260 of the extrusionpress system 200.

The mandrel grips 106, 108 comprise a mandrel bar gripping system 105designed to hold the mandrel bar in place while allowing a plurality ofbillets to be continuously fed along and about the mandrel bar 100 toprovide for continuous extrusion. The billets may be formed from anysuitable material for use in extrusion press systems including, but notlimited to, various metals including copper and copper alloys, or anyother suitable non-ferrous metals such as aluminum, nickel, titanium,and alloys thereof, ferrous metals including steel and other ironalloys, polymers such as plastics, or any other suitable material orcombinations thereof. The mandrel grips 106, 108 may be controlled bythe PLC system to securely hold in place and prevent the mandrel bar 100from rotating such that at any given time during the extrusion process,at least one of the mandrel grips 106, 108 is gripping the mandrel bar100. The mandrel grips 106, 108 set the position of the mandrel bar 100and prevent the mandrel bar 100 from rotating. When the mandrel grips106, 108 are in a gripping or engaged position, thereby gripping themandrel bar 100, the mandrel grips 106, 108 prevent billets from beingtransported along the mandrel bar 100 through the grips.

The mandrel grips 106, 108 operate by alternately gripping or engagingthe mandrel bar 100 to allow one or more billets to pass through arespective mandrel grip at a given time. For example, the upstreammandrel grip 106 may release or disengage the mandrel bar 100 while thedownstream mandrel grip 108 is gripping the mandrel bar 100. At anygiven time, at least one of the mandrel grips 106, 108 is preferablygripping or otherwise engaged with the mandrel bar 100. One or morebillets queued or indexed near the upstream mandrel grip 106, or beingtransported along the mandrel bar 100, may pass through the openupstream mandrel grip 106. After a specified number of billets haspassed through the open upstream mandrel grip 106, the gripper 106 mayclose and thereby return to gripping the mandrel bar 100, and thebillets may be advanced to the downstream gripping element 108. Thedownstream gripping element 108 may remain closed, thereby gripping themandrel bar 100, or the downstream mandrel grip 108 may open after theupstream mandrel grip 106 re-grips the mandrel bar 100. Although twomandrel grips 106, 108 are shown in the extrusion press system 10, itwill be understood that any suitable number of mandrel grips may beprovided.

The fluid clamps 102, 104 comprise a mandrel bar fluid delivery system101 designed to supply cooling fluid along the interior of the mandrelbar 100 to the mandrel bar tip during the extrusion process. The fluidclamps 102, 104 also receive cooling fluid from the mandrel bar 100 thathas returned from the mandrel bar tip. Any suitable cooling fluid may beused, including water, various mineral oils, brines, synthetic oils, anyother suitable cooling fluid, including gaseous fluids, or anycombination thereof. The fluid clamps 102, 104 may be controlled by thePLC system to continuously supply process cooling fluid to the mandrelbar during the extrusion process while allowing a plurality of billetsto be continuously feed along and about the mandrel bar 100. The fluidclamps 102, 104 operate such that there is no or substantially nointerruption to the supply of process cooling fluid to the mandrel bartip during the extrusion process. Similar to the operation of themandrel grips 106, 108 discussed above, when the fluid clamps 102, 104are clamped to or engaged with the mandrel bar 100, the fluid clamps102, 104 prevent billets from being transported along the mandrel bar100 through the fluid clamps.

The fluid clamps 102, 104 operate such that at any given time during theextrusion at least one of the fluid clamps is clamped to or engaged withthe mandrel bar 100 and thereby delivers cooling fluid into the mandrelbar 100 for delivery to the mandrel bar tip. When a billet passesthrough one of the fluid clamps 102, 104, the respective fluid clampdiscontinues delivering (and receiving) cooling fluid and releases ordisengages the mandrel bar 100 to allow the billet to pass therethroughbefore re-clamping the mandrel bar 100 and continuing to deliver (andreceive) cooling fluid. While one of the fluid clamps 102, 104 isunclamped or disengaged from the mandrel bar 100, the other fluid clampcontinues to deliver cooling fluid to the mandrel bar.

For example, the upstream fluid clamp 102 may release the mandrel bar100 while the downstream fluid clamp 104 is clamped to the mandrel bar100. At any given time, at least one of the fluid clamps 102, 104 ispreferably clamped to the mandrel bar 100 to continuously delivercooling fluid. One or more billets queued or indexed near the upstreamfluid clamp 102, or being transported along the mandrel bar 100, maypass through the open upstream fluid clamp 102. After a specified numberof billets has passed through the open upstream fluid clamp 102, thefluid clamp 102 may close and thereby return to clamping the mandrel bar100 and delivering cooling fluid, and the billets may be advanced to thedownstream fluid clamp 104. The downstream fluid clamp 104 may remainclosed, thereby clamping the mandrel bar 100, or the downstream fluidclamp 104 may open after the upstream fluid clamp 102 re-clamps to themandrel bar 100. Although two fluid clamps 102, 104 are shown in theextrusion press system 10, it will be understood that any suitablenumber of fluid clamps may be provided.

The billet delivery system ensures that a continuous supply of billetsis present for the extrusion process. When additional billets areneeded, the PLC system will cycle the proper mandrel bar grips 106, 108,fluid clamps 102, 104, and billet delivery rollers to ensure that thebillet supply is continuous. The section of the mandrel carriage 280located between the mandrel grip 106 and the entry platen 120 maycontinuously index to minimize the gap between billets fed into the ramplaten sections 141 of the platen structure 290. For example, at thislocation of the mandrel carriage 280, the track assembly maycontinuously cycle the track to feed billets into the platen structure290.

The mandrel bar 100 extends along substantially the length of theextrusion press system 200 and is positioned to place the mandrel bartip within the rotating die 160. The adjustment to properly position themandrel bar tip within the rotating die 160 is accomplished by movingthe mandrel carriage section 280, thus moving the mandrel bar 100. Theadjustments to the mandrel bar 100 and the mandrel carriage section 280may be towards or away from the die 160. The mandrel bar 100 and themandrel carriage section 280 preferably cannot be adjusted while theextrusion press system 200 is in operation, although it will beunderstood that in certain embodiments the mandrel bar 100 and/ormandrel carriage section 280 may be adjusted during operation.

As discussed above, the extrusion press system 200 includes a platenstructure section 290 having an entry platen 120 and a rear die platen122, press-ram platens 130 and 140, a centering platen 152, and arotating die 160 pressed against the rear die platen 122. Near the entryplaten 120 is the press-ram assembly 141 that includes a first press-ramplaten 130 and a second press-ram platen 140. The first and secondpress-ram platens 130, 140 feed billets into the centering platen 152,which grips the billets and prevents the billets from rotating prior toentering the rotating die 160, which presses against the rear die platen122. The entry platen 120 and the rear die platen 122 are coupled by aseries of tie rods 124 that act as guides for the press-ram platens 130,140 and the centering platen 152, each of which includes bearings 126 a,126 b, 126 c that move along the tie rods 124. The rear die platen 122and the entry platen 120 have mounting locations 127 through which thetie rods 124 are fixed. The entry platen 120, rear die platen 122, andtie rod structure 124 are supported by the frame 190. The frame 190 alsoholds the spindle 172 and motor 170. At the exit of the rotating die 160is a quench tube 180 for rapidly cooling the extruded tubing.

The press-ram platens 130, 140 operate by gripping the billets andproviding a substantially constant pushing force in the direction of theextrusion die stack 160. At any given time at least one of the press-ramplatens 130, 140 grips a billet and advances the billet along themandrel bar 100 to provide the constant pushing force. The press-ramplatens 130, 140 form the final part of the billet delivery subsystem220 before the billet enters the centering insert 150 of centeringplaten 152 and the rotating die 160 of the extrusion subsystem 240.Similar to the billet feed track section before the entry platen 120,the section prior to the press-ram platens 130, 140 preferablycontinuously indexes the billets to minimize any gaps between a billetthat is gripped the press-ram platens 130, 140 and the next billet.

As discussed above, the press-rams 130, 140 continuously push billetsinto the rotating die 160. The press-rams 130, 140 alternate grippingand advancing billets towards and into the rotating die 160 and thenungripping the advanced billets and retracting for the nextgripping/advancing cycle. There is preferably an overlap between thetime when one press-ram stops pushing and the other press-ram is aboutto start pushing so that there is always uniform pressure on therotating die 160. The press-rams 130, 140 advance and retract viapress-ram cylinders coupled to the respective press-ram. As shown thereare two press-ram cylinders 132, 142 per press-ram. A first set ofpress-ram cylinders 132 is located to the left and right of the entryplaten 120 (although the right-side press-ram cylinder is hidden fromview by the left-side press-ram cylinder). The first set of press-ramcylinders 132 couples with the first press-ram platen 130 and isconfigured to move the first press-ram 130 along the tie rods 124 as thefirst press-ram 130 advances billets and then retracts for subsequentbillets. A second set of press-ram cylinders 142 is located on the topand bottom of the entry platen 120. The second set of press-ramcylinders 142 couples with the second press-ram platen 140 and isconfigured to move the second press-ram 140 along the tie rods 124 asthe second press-ram 140 advances billets and then retracts forsubsequent billets. Although two press-ram cylinders are shown for eachof the first and second press-ram platens 130, 140, it will beunderstood that any suitable number of press-ram cylinders may beprovided. In certain embodiments, press-ram cylinders may be coupled toboth press-rams 130, 140.

The centering platen 152 receives billets advanced by the press-rams130, 140 and functions to hold the billets during the extrusion processprior to entry of the billets into the rotating die 160. When thecentering platen 152 is positioned in place for the extrusion process,the centering platen 152 substantially becomes part of the extrusion die160. That is, a centering insert 150 of the centering platen 152substantially abuts the rotating die 160. The centering platen 152itself, however, and the components therein including the centeringinsert 150, do not rotate with the rotating die 160. The centeringplaten 152 prevents billets that are no longer held by the secondpress-ram 140 from rotating while the die 160 rotates by gripping thebillets and thereby preventing the billets from rotating prior to entryof the billets into the rotating die 160.

As discussed above, the extrusion press system 200 includes positivestops 154, 156. The positive stops 154, 156 are coupled to a firstsupport structure 162 and extend towards a second support structure, thecentering platen 152, with a gap between contact surfaces of therespective components that amounts to a travel distance. Duringoperation, the first support structure 162 is stationary and the secondsupport structure 152 moves relative to the first support structure 162.For example, one or more piston/cylinder drive units (similar to thepress-ram cylinders discussed above with respect to the press-ramoperation) may be coupled to the support structure 152 to advance andoptionally retract the structure along the tie rods 124. In certainembodiments, the second support structure 152 moves in a directiontowards the first support structure 162 (along arrow B) and a directionaway from the first support structure (opposite arrow B). The positivestops 154, 156 therefore define a travel distance between the respectivesupport structures 162, 152. Although the positive stops 154, 156 areshown as coupled to and extending from the first support structure 162towards the second support structure 152, other configurations may beused. For example, in some embodiments, a positive stop may be coupledto the second support structure 152 and extend towards the first supportstructure 162, with a gap between respective contact surfaces of thepositive stop and first support structure 162. Any suitable arrangementfor preventing motion of one (or more) of the support structures may beused.

The rotating die 160 may have a unibody design, or may include aplurality of die plates stacked together. In certain embodiments, thedie includes a base plate, a final plate, a second intermediate plate, afirst intermediate plate, an entry plate, and a steel end holder, andthe die plates are bolted together or otherwise coupled to form the die160. In some embodiments, additional plates may be added to form therotating die. The rotating die 160 is bolted to or otherwise coupledwith the spindle 172, which is operated by the motor 170. A gear box isbolted to the rear die platen 122 and contains the spindle 172 as wellas the drive chain, motor drive gear, gear oil reservoir, and gear oilheat exchanger, which are not shown in FIG. 5 to avoid overcomplicatingthe figure. In certain embodiments, the spindle motor 170 and thespindle/die gear tooth ratio is 2.5:1, although it will be understoodthat any suitable gear ratio may be used for the rotation of therotating die 160.

At the extrusion end of the extrusion press system 200 is a quench box185 bolted or otherwise coupled to the exit side of the gear box on therear die platen 122. In certain embodiments, within the quench box 185is a quench tube 180 for rapidly quenching or cooling the extrudedmaterial as it exits the rotating die 160. Water may be used as thequenching or cooling fluid, and the water may contact the extrudedmaterial sometime after the exit of the extruded material from therotating die 160. For example, in certain embodiments, the extrudedmaterial is quenched with cooling fluid within approximately 1 inch, orless, of exiting the rotating die 160. Any suitable cooling fluid may beused for quenching an extruded material, including water, variousmineral oils, brines, synthetic oils, any other suitable cooling fluid,including gaseous fluids, or any combination thereof. The quench tube180 may be formed of one or more tubes having a channel therein fordelivering the cooling fluid to the extruded material. In certainembodiments, the quench tube 180 further includes an end cap or otherstructure through which the cooling fluid is delivered to the extrudedmaterial. Any suitable quench tube may be used the extrusion presssystem of this disclosure.

In certain embodiments, nitrogen gas, or another suitable inert gas, isdelivered to the interior of an extruded material as the material exitsthe rotating die. For example, nitrogen gas may be delivered to theinterior of extruded tubing using a cap placed on the leading end of theextruded tubing as it exits the rotating die. Injecting gaseous orliquid nitrogen into the rotating die assembly, or the interior of theextruded material itself, can minimize oxide formation by displacing theoxygen-laden air.

The foregoing is merely illustrative of the principles of thedisclosure, and the systems, devices, and methods can be practiced byother than the described embodiments, which are presented for purposesof illustration and not of limitation. It is to be understood that thesystems, devices, and methods disclosed herein, while shown for use inextrusion press systems, may be applied to systems, devices, and methodsto be used in other manufacturing procedures including, but not limitedto, cast-and-roll, up-casting, other extrusion, and other manufacturingprocedures.

Variations and modifications will occur to those of skill in the artafter reviewing this disclosure. The disclosed features may beimplemented, in any combination and subcombination (including multipledependent combinations and subcombinations), with one or more otherfeatures described herein. The various features described or illustratedabove, including any components thereof, may be combined or integratedin other systems. Moreover, certain features may be omitted or notimplemented.

Examples of changes, substitutions, and alterations are ascertainable byone skilled in the art and could be made without departing from thescope of the information disclosed herein. As used herein, the term“about” refers to a number that varies by up to 5%, or in otherembodiments up to 10%, and in other embodiments up to 25%, from thenumber being referred to. The allowable variation encompassed by theterm “about” will depend upon the particular system, and can be readilyappreciated by one of ordinary skill in the art. Whenever a range isrecited within this disclosure, every whole number integer within therange is also contemplated as an embodiment of the disclosure. Allreferences cited herein are incorporated by reference in their entiretyand made part of this application.

1. An extrusion press system comprising: an extrusion die supported by afirst support structure; a centering insert supported by a secondsupport structure, wherein the centering insert guides a material to beextruded into the extrusion die; and a positive stop coupled to thefirst support structure and extending towards the second supportstructure, wherein the positive stop defines a travel distance betweenthe first support structure and the second support structure.
 2. Theextrusion press system of claim 1, wherein the extrusion die rotateswithin the first support structure.
 3. The extrusion press system ofclaim 2, wherein the centering insert is positioned against theextrusion die and does not rotate.
 4. The extrusion press system ofclaim 3, wherein the centering insert comprises gripping features thatfrictionally engage the material to be extruded and thereby prevent thematerial from rotating while engaged and as the material enters therotating extrusion die.
 5. The extrusion press system of claim 1,wherein the first support structure is stationary, and wherein thesecond support structure is configured to move relative to the firstsupport structure.
 6. The extrusion press system of claim 5, whereinmovement of the second support structure towards the first supportstructure is limited by the positive stop to the travel distance.
 7. Theextrusion press system of claim 5, wherein the centering insert is aconsumable part that is partially consumed when the second supportstructure moves towards the first support structure a distance of thetravel distance.
 8. The extrusion press system of claim 1, wherein thepositive stop is configured to adjust the travel distance.
 9. Theextrusion press system of claim 8, wherein the positive stop comprisesan adjustable portion that rotates about a threaded shaft for increasingor decreasing the travel distance.
 10. The extrusion press system ofclaim 8, wherein the positive stop comprises an adjustable portion thatslides along a shaft for increasing or decreasing the travel distance.11. The extrusion press system of claim 8, wherein the positive stopcomprises a recess configured to mate with a plurality of end portions,each respective end portion having a respective thickness for increasingor decreasing the travel distance.
 12. The extrusion press system ofclaim 10, wherein the positive stop further comprises a through-holeinto which a locking pin is positioned.
 13. The extrusion press systemof claim 1, further comprising a second positive stop.
 14. The extrusionpress system of claim 1, wherein the travel distance is between aboutzero inches and about 100/1000 inch.
 15. The extrusion press system ofclaim 14, wherein the travel distance is about 20/1000 inch.
 16. Amethod for extruding a material comprising: positioning a centeringinsert in a first position against an extrusion die; exerting a force onthe centering insert to maintain a desired pressure of the centeringinsert against the extrusion die, wherein the force moves the centeringinsert from the first position to a second position; and preventingfurther movement of the centering insert at the second position.
 17. Themethod of claim 16, wherein upon preventing further movement, a pressureof the centering insert against the extrusion die decreases relative tothe desired pressure.
 18. The method of claim 16, wherein the forcecontinues to be exerted while movement of the centering insert isprevented at the second position.
 19. The method of claim 16, wherein adistance between the first position and the second position defines atravel distance.
 20. The method of claim 19, further comprisingadjusting the travel distance.
 21. The method of claim 16, wherein theextrusion die rotates, and wherein the centering insert does not rotate.22-36. (canceled)